Line-spacing apparatus



M r h 1969 H. GAISSERT ETAL LINE-SPACING APPARATUS Sheet 1 of 5' Filed April 19, 1966 INVENTORS. HE/NZ GAISSERT JOHANNES H/LLER March 1969 H. GAISSERT ETAL 3,433,345

LINE- SPACING APPARATUS Filed April 19. 1966 Sheet 2 of 5 INVENTORS HE/NZ GA/SSERT JOHANNES m1. LER

ATTORNEY March 8. 1969 H. GAISSERT ETAL 3,433,345

LINE- SPACING APPARATUS Sheet Filed April 19. 1966 Fig. 2b

, INVENTORS HE/NZ GAISSERT JOHA/WVES MILLER ,0 BY 7 Q United States Patent 3,433,345 LINE-SPACING APPARATUS Heinz Gaissert and Johannes Hiller, Pforzheim, Germany,

assignors to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware Filed Apr. 19, 1966, Ser. No. 543,605 Claims priority, application Germany, Apr. 22, 1965,

St 23,719 0 Us. (:1. 197-114 6 (31211115 rm. (:1. B41j19/80 ABSTRACT OF THE DISCLOSURE The present invention relates to a line-spacing mechanism for high speed printing telegraph apparatus. To achieve exact line-spacing in the case of high switching speeds, the line traversing motion is adjusted by varying the lever ratios of a feed pawl which, at normal, is disengaged from the ratchet wheel, and is limited by means of a stationary limit stop locking the feed pawl to the ratchet wheel.

Since the line-spacing oepration must be carried out within the period of a teleprinter element, conventional line-spacing mechanisms are not suitable for the requirements of high speed operation.

In one known arrangement, a line-spacing mechanism is provided in which, by the adjustment of a roller lever, a feed pawl, motion includes a large idle stroke before coming into engagement with the ratchet wheel. At the end of this stroke or length of travel, the feed pawl contacts a stationary limit stop, and there is effected a latching in the forward or feed direction between the feed pawl and the ratchet wheel without excessive sideslip. This arrangement has a disadvantage in that the pawl, because of the idle stroke, suddenly comes into engagement with the ratchet wheel causing increased wear and unnecessary noise, and only utilizes the full length of travel of the operating stroke for maximum line spacing.

Another arrangement for effecting a line-traversing motion overcomes the disadvantages of an idle stroke by a feed pawl which is continuously in engagement with the ratchet wheel permitting the adjustment of the line-traversing motion by varying the lever ratios in each setting so that the entire stroke is utilized. However, this arrangement does not prevent excessive line-spacing because different stop limit positions of the pawl are assigned to the different traversing motion positions. Moreover in this arrangement, the pawl is continuously in engagement with the ratchet wheel and prevents turning back of the platen by hand until after it has been lifted.

All of these disadvantages are avoided by the line-spacing mechanism according to the present invention, wherein a lifted pawl, in the normal position, permits a continuous maximum utilization of the length of travel, and provides that the intended line traversing motion is exactly adhered to. Accordingly, the variation of the lever ratio determining the degree of line-spacing is linked to a concentrical adjustment of the feed pawl corresponding to the line traversing motion which results, in respect to the defined end position, that the feed pawl, in co-operation with a stationary catch pawl, establishes a positive- 3,433,345 Patented Mar. 18, 1969 locking connection between the ratchet wheel and the stationary parts of the apparatus during the time of direction reversal.

The invention will now be explained in detail with reference to the accompanying drawing, in which:

FIG. 1, in a perspective representation, shows the embodiment of a line-spacing mechanism according to the invention;

FIG. 1a shows the lower part of the pull strap, which is partly shown in FIG. 1, and the associated actuating mechanism; and

FIGS. 2a and 2b schematically show the line-spacing mechanism of FIG. 1, both in a normal condition and at the time when the pawl reaches its end position.

Referring now to FIGURE 1, there is shown part of the machine frame 1 through which shaft 2 of the platen 3 and shaft 5 of the paper pressure rollers 4 are mounted. Both the shaft 2 and the shaft 5 project through the frame portion 1 as shown and mount the most substantial portions of the line-spacing mechanism. On shaft 2 a ratchet wheel 7 is firmly arranged, followed by a freely rotatable adjusting bracket 11 between which a function rocker arm 9 is also pivoted in a freely rotatable manner. A knurled turning button 6 is firmly secured on the end of shaft 2 for manual line adjustment. A hand lever 17 is both pivotally and slidably mounted on shaft 5 at two points in a straplike manner extending around the frame portion 1 as shown. Between the end of the shaft 5 and the wall of the frame 1, in alignment with the ratchet wheel 7, are pivotally mounted a catch pawl 20 and an index lever 18. A spring 22 is biased to force hand lever 17 against the inside of the frame portion 1 adjacent the platen 3. The hand lever 17 is used for manual setting of the distances between the lines in accordance with the numerical markings 1a corresponding to the engaging holes 1b in the frame portion 1. The hand lever 17, via its engaging bolt 17a, is engaged in a selected adjusting position as shown.

A pin 17b on hand lever 17 engages a slot 14b to determine the position of roller 14a of pull strap 14 on function arm 90, and the pull strap 14 thereby transfers the machine line-spacing travel to rocker arm 9. As shown in FIGURE 1a, pull strap 14 is pivotally connected to a pull lever 15 by a bolt 15a which, upon actuation of the line-spacing function, always traverse the angle h.

The hand lever 17 is also in a positive locking connection with the adjusting bracket 11 by a pin 17c and slot 11b. The bracket 11 is capable of being adjusted in several positions by the hand lever 17, and the bracket 11 is provided with a limit stop bolt 11a which provides a counter support for the function rocker arm 9 when the arm is in its normal position and under the action of a spring 19. The adjusting bracket 11 has in alignment with the feed pawl 8 an inclined ramp member 12. The feed pawl 8 is pivotally arranged on the arm 9a of the function rocker arm 9. In its normal position and in opposition to the action of a spring 8a, pawl 8 is retained out of engagement with the ratchet wheel 7 by ramp member 12. A limit stop 10 on the frame portion 1 is used for the stroke-or travellimiting of the pawl 8 and the ratchet wheel 7 so as to avoid excessive line-spacing effects. Therefore, at the end of the line-spacing motion, feed pawl 8 establishes positive contact with limit stop 10, so that the stationary parts of the apparatus absorb the kinetic energy stored in the platen 3 to prevent any extra line-spacing.

The function rocker arm 9 includes a guide bushing 9a which is freely rotatable on the shaft 2, and, on the side facing the ratchet wheel 7, a double lever consisting of a pawl arm 9a and of a lifting arm 9b, and, on the opposite side, a function arm 90. The lifting arm 9b is angled off at its end. By means of the free limb, the catch pawl 20 by its pin 20a is retained in the normal position of the function rocker arm 9 and, during a certain period of each line-space travel, is retained out of engagement with the ratchet wheel 7. A spring 19 engages the lifting arm 9b and, by being oppositely suspended on the index lever 18, simultaneously also serves to effect the spring action of the index lever 18 against the ratchet wheel 7.

By means of roller 14a on the function arm 90, the pull strap 14 acts upon the line spacing apparatus. The function arm 90 is provided with a smooth sliding surface extending slantingly in direction to the pull direction and corresponding to the angle 12 traversed by lever 15. Both the inclined position and the sliding surface are chosen so that in the case of a pulled strap 14 (FIG. 2b) the slide surface profile at the point of contact with the roller 14a will always lie on the circular are determined by the pivotal movement of strap 14 about its pivot 150. This sliding surface may be designed in a straight-lined fashion whenever the pull strap 14 has a predetermined minimum length. In this way it is assured that in all line distance positions of the hand lever 17, there is effected a displacernent of the roller 14a on the sliding surface of the anm 9c, and the effective lever length of the function arm 9c modifying the length of travel is such that the function rocker arm 9' and the feed pawl 8 will always assume a stroke or travel end position which is the same.

When changing the line-traversing motion setting, there will result, through pin 17b and slot 14b, an angular adjustment of the pull strap 14 which is directed from the maximum value setting 2 to the minimum value setting 1 on the sliding surface 90, so that in the unactuated position, as shown in FIGURE 2a, it extends slopingly. Necessary clearance is maintained between the sliding surface and the roller 14a together with the pull strap 14. The adjusting bracket 11, by means of pin 17c and slot 11b, is adjusted and causes the function rocker arm 9 which is biased by spring 19 to press against the limit stop 11a, Due to the adjustment of the function rocker arm 9, the pawl 8 is caused to follow the inclined ramp member 12 mounted on the bracket 11 and its position is chosen so that the platen 3 can be freely turned backwards and forwards by hand, but the idle stroke is as small as possible.

The engaging positions of the hand lever 17 result from the adjusting positions of the adjusting bracket 11 which are adapted to the tooth pitches of the ratchet wheel 7. The adjusting angles are set to one or a multiple of one tooth pitch of the ratchet wheel 7.

In order to assure in the normal condition a fixed posi tion of the platen 3, there is provided the indexing lever 18 which, under the effect of the springs 19, 20b and its engaging member 18a, is vertically adjustable and is in continuous engagement with the ratdhet Wheel 7.

With reference to FIGS. 2a and 2b and to What has been described hereinbefore, the functional sequence of one switching cycle will be explained.

In the two schematical representations, the setting for a double line-spacing operation is indicated in solid lines, Whereas the settings for a one-line and a one-and-a-halfline spacing are indicated by the dot-and dash-lines.

Extending from the normal condition as shown in FIG. 2a, the feed p awl 8, due to the support of the inclined ramp member 12 and the function rocker arm 9 being against the limit stop 11a, is kept out of engagement with the ratchet wheel 7 until there is effected the line spacing motion by the actuation of pull strap 14 by the pull lever 15. The pull strap 14 acts upon the function arm 90 via the slide roller 14a, and causes a swivelling of the function rocker arm 9 in the clockwise direction. The feed pawl 8 is pulled along therewith and slides off the inclined ramp member 12 which remains in its position, and comes into engagement with the ratchet wheel 7. The ratchet wheel 7 is taken along an angular path resulting from both the effective lever length, as determined by the point of engagement of the slide roller 14a with the function arm 90, and angle h.

FIG. 2b shows the end position which is the same for all three settings, and in which the function arm with the profile of its sliding surface is lying on the circular are around the center of rotation of the pull strap extending through the point of contact between the slide roller 14a and the sliding surface of the function arm 90. After lever 15 has traversed the angle h, the feed pawl 8 has not quite reached its end position, and the last fraction is travelled by the feed pawl 8 and the moving function rocker arm 9 due to inertia of the system until the latching of the ratchet wheel 7 through the feed pawl 8 and the limit stop 10. The line-spacing movement is limited by the latching action on the ratchet wheel 7 in the linetraversing direction and thereby prevents an excessively line-spacing. As soon as the feed pawl 8 approaches the end position, the catch pawl 20 (not shown in FIGS. 2a and 2b) is released by the lifting arm 9b and the action of its spring 20b, and engages the ratchet wheel 7. This catch pawl 20 is adjusted so that its pawl tooth, shortly before the feed pawl 8 has reached its final position, will engage behind a tooth of the ratchet wheel 7. This engaged position is retained by the catch pawl 20 during the rearward movement of the function rocker arm 9. Accordingly, the ratchet wheel 7 and the platen 3 are, for the time of the direction reversal of the moving elements 8 and 9, in a positive locking connection with the machine frame 1 by means of the limit stop 10 and the catch pawl 20. In this manner it is possible to absorb or avoid the extra line spacing and bouncing phenomena caused by the kinetic energy which is stored in the platen 3. This is more likely to occur in the end position in the case of high linetraversing speeds, which makes exact line-spacing difficult.

In flhe course of resetting the function rocker arm 9 to the normal position of FIGURE 2a, under the action of the spring 19, the catch pawl 20 is disengaged from the ratchet wheel 7 !by the lifting arm 9b, and the feed pawl 8 slides back onto the inclined ramp member 12. The ratchet wheel 7 is then free so that a manual setting of the platen 3 is possible at any time. The indexing lever 18 with its engaging memlber 18a, does not affect the free backward and forward rotatability of the platen 3, since it maintains the selected platen position by resiliently pressing upon the ratchet wheel 7.

We claim:

1. A line-spacing appartus comprising:

a machine frairne, one wall of said frame having a plurality of engaging holes for determining the degree of line spacing;

a first shaft rotatably mounted through said one wall;

a platen attached to said first shaft and located on one side of said one wall;

a ratchet wheel mounted on said first shaft and located on the other side of said one wall;

a function rocker arm rotatably arranged on said first shaft and coaxially in relation to said ratchet wheel;

a second shaft, parallel to said first shaft and mounted through said one wall;

a hand lever capable of being swiveled on said second shaft for engaging one of said plurality of holes for determining the degree of line spacing;

a feed pawl, pivotally arranged on said rocker arm for engaging said ratchet wheel;

an adjusting bracket, swivelly mounted on said first shaft, with a limit stop bolt which, in its normal condition, is in a force-locking connection with said rocker arm, and with an inclined ramp member to effect the lifting of said feed pawl, said adjusting bracket further including a slot guide which forms a positive locking connection with said hand lever, such that said adjusting bracket is capable of being adjusted in several positions by said hand lever;

a catch pawl mounted on said second shaft and positioned to engage said ratchet wheel;

means for establishing a positive locking connection between said feed pawl and said ratchet wheel; and

means cooperating with said rocker arm to control the line spacing motion, said means including a pull strap wherein the effective connection between said pull strap and rocker arm controls the engagement of said feed pawl with said ratchet wheel, such that, at the end of the line spacing function, there i is established a positive locking connection between the ratchet wheel and the machine frame.

2. Apparatus according to claim 1, in which said pull strap has a positive locking guide to form a positive locking connection with said hand lever, such that the position of said hand lever determines the position of said pull strap on said rocker arm, which position on actuation of said pull strap will correspond to the degree of line spacing 3. Apparatus according to claim 2, in which the surface of said rocker arm which is in an effective connection with said pull strap is smooth, and so designed that the points of contact during the mutual readjustment of said rocker arm and pull strap are lying on the corresponding circular are about the center of rotation of said pull strap, and in the actuated condition of said pull strap, this surface of said rocker arm is lying with its profile on the circular are about the center of rotation of said strap extending through the point of contact.

4. Apparatus according to claim 3 wherein in said catch pawl contains a pin, such that in the normal position said catch pawl is retained out of engagement with said ratchet wheel by said rocker arm, and at the end of the line spacing function said catch pawl engages said ratchet wheel to establish a positive locking connection with the madhine frame.

5. Apparatus according to claim 4 further including an indexing lever, mounted on said second shaft and resiliently acting upon said ratchet wheel to fix the position of the platen during inoperative periods.

6. Apparatus according to claim 5, wherein a spring is connected lbetween said indexing lever and said rocker arm such that said spring reutrns said rocker arm to a normal position after a line spacing function has been completed.

References Cited UNITED STATES PATENTS 345,347 7/1886 Whaley 197-114 832,244 10/1906 Dennis 197114 1,243,110 10/1917 Roebuck 197114 1,360,747 11/ 1920 Helmond 19'71l4 1,672,354 6/1928 Ty berg 197114 X 2,303,879 12/1942 Helmond 197-114 2,453,282 11/1948 Thieme 19'7-114 2,775,332 12/1956 Wohlbier 197114 2,791,311 5/1957 Yerks et a1. 197114 2,902,134 9/1959 Dodsworth 197-1 14 3,263,793 8/1966 Brignole 197120 ERNEST T. WRIGHT, Primary Examiner. 

